Maximization of concentrated solar thermal (CST) technology performance and minimization of operational expenditures (OPEX) requires considering not only the solar resource, but also other effects, such as soiling. Dust accumulation modifies the optical properties of solar collectors and mirror surfaces leading to a significative reduction of the useful solar energy [1], [2]. Current research points out that soiling can decrease specular reflectance by about 10% per month in low soiling regime regions and higher than 40% in locations with high atmospheric aerosol loads, such as deserts [3]. Thus, soiling stands out as one of the most impactful factors to be considered when evaluating CST performance and corresponding OPEX. Nonetheless, soiling assessment is still usually performed in CST technologies manually by operators at solar fields with portable reflectometers, which is not only time consuming, but not feasible for large plants. On the other hand, although automatic instruments, such as the Tracking Cleanliness Sensor (TraCS) [4] or the AVUS Instrument [5], only do spatial punctual measurements, which means that for bigger solar fields and for a precise soiling assessment, multiple ones have to be bought, increasing the capital expenditures (CAPEX). Additionally, there is no current instrumentation to measure soiling effect in Fresnel secondary optics or Stirling dishes, due to their height and size.
Therefore, the development of new techniques is needed to automatize and generalize soiling assessment for all CST technologies, while simultaneously making it faster and able to measure a greater number of units. In this project, a novel technique using a 3D laser scanner will be developed and tested at real solar fields, such as the one at IMDEA Energy (IMDEA), Spain and at the Cyprus Institute (CYI), Cyprus.
Measurements will be compared with reflectometer data aiming to establish a model with an absolute reflectance error < 2%. It is noted that some preliminary tests were previously performed at IMDEA, Figure 1, showing promising results.
Team:
Marios Georgiou, Kypros Milidonis, and Alaric Montenon
Website:
Contact Person:
Funding:
European Commission/Horizon 2020
Partners:
Fundacion IMDEA Energia IMDEA ES
Fraunhofer Gesellschaft zur Förderung angewandten Forschung EV (Fraunhofer)
The Cyprus Institute CyI
